This invention relates to a reservoir for a fluid or powder product, a method of filling this reservoir, and a device for dispensing, as a single unit, a dose of powder contained in this reservoir using a flow of compressed air.
Expressed in another way, the invention relates more specifically to a device comprising one or more separate, pre-dosed reservoirs, each containing a single dose of product. When there is only one reservoir, the device is a mono-dose device. However the invention is equally applicable to multi-dose type devices, for example two dose or four dose devices, comprising several pre-dosed reservoirs, which allow, notably, a balancing of doses given to both nostrils in the case of nasal application.
Similarly, although the invention can be used with fluid or powder products, it is more particularly applicable to the dispensation of doses of powder and in what follows, reference will be made to this type of product. In effect, the field of powdered products to be dispensed by inhalation, in particular medication based on dry powder, is being developed more and more since dry powder formulations offer numerous advantages compared with liquid suspensions or liquid solutions. They are notably more stable and require neither a solvent nor a preserving agent.
Document EP-0 404 276 discloses a dispenser for a powder or a fluid product which comprises a product reservoir and a gas chamber, in this case the gas being air, and a plunger that can be displaced relative to the reservoir. The reservoir includes an inlet orifice and an outlet orifice, the inlet orifice being blocked by a membrane which separates the reservoir from the gas chamber. Hence, when the device is actuated, the plunger is displaced in the gas chamber, which compresses the air downstream from the membrane until a perforating member integral with the plunger pierces said membrane which allows the flow of air under pressure to pass through the product chamber from its inlet orifice to its outlet orifice carrying a dose of product with it. The main disadvantage of this device is that the outlet orifice from the reservoir is only protected by the detachable cap that the user removes before actuating the device. Hence, between removing the detachable cap and actuating the device, there is a risk of contaminating the product and/or losing the product in the event of handling the device in the wrong way.
In order to resolve this problem, dispensation devices have been proposed in which the outlet orifice from the reservoir is also blocked by a membrane. Hence, when the device is not being used, the inlet and the outlet orifices are blocked in a sealed fashion and the product contained in the reservoir does not risk being contaminated or lost. It is only at the time that the product is being dispensed that the inlet and outlet orifices are unblocked allowing passage of the flow of air which carries the dose of product to the outside of the device. This type of dispenser finds particular application in the field of dispensation of pharmaceutical products in the form of powder, notably by nasal administration. Such a device is notably disclosed in document WO 93/11818.
A problem which does occur with this type of device relates to the piercing of the membrane which blocks the outlet orifice from the reservoir. In effect, it frequently happens that the membrane does not completely unblock the outlet orifice from the reservoir which means that the product can remain built up inside the reservoir on those parts of the membrane that are at the level of the outlet orifice. The result is that not all of the dose of product is dispensed, which particularly in the case of medical treatment is not generally acceptable since a precise and total administration of the dose contained in the reservoir is often a condition for the effectiveness of the treatment.
One aim of this invention is to provide a reservoir for a fluid or powder product and a dispensing device which does not have the disadvantages mentioned above.
A particular aim of this invention is to provide a device for the dispensing of a fluid or powder product which ensures complete and precise dispensation of the dose of product contained in the reservoir.
Another aim of this invention is to provide a device for dispensation of a fluid or powder product which ensures a finely sprayed administration of the dose of product contained in the reservoir.
Another aim of this invention is to provide a reservoir for a fluid or powder product and a dispensation device which are simple and inexpensive to manufacture and to assemble.
A further aim of this invention is to provide a reservoir for a fluid or powder product and a dispensation device that prevents any risk of contamination of the dose of product before its administration to the user of the device.
Another aim of this invention is to provide a device for the dispensation of a fluid or powder product which can be used several times with different pre-dosed reservoirs.
Another aim of this invention is to provide a method of filling such a reservoir which is the most simple and economic possible.
Therefore the subject of this invention is a reservoir for a fluid or powder product containing a single dose of product, the reservoir comprising an air inlet and a product outlet, said air inlet comprising a product retention device to keep the product in the reservoir until dispensation of the product, said product outlet being blocked, preferably in sealed fashion, by a closing ball which is removed from its blocking position by an air flow created at the time of dispensation of the product.
Preferably the device for retaining the product is permeable to air.
Advantageously, the product is a powder and the powder retaining device is a grid, the openings of which have dimensions less than the particle size of the powder.
Advantageously, the air inlet of the reservoir is blocked by a closing membrane that forms a seal to both product and air.
Preferably, downstream from said membrane in the direction of the air flow, the reservoir comprises said grid permeable to the air and which does not allow passage of the powder, in order to retain the powder in the reservoir after the closing membrane has been opened.
Preferably, said ball is removed from its blocking position when a minimum pre-determined pressure is created in the reservoir by said air blast.
According to one preferred embodiment, the reservoir comprises a cylindrical sleeve to receive the dose of powder, said sleeve incorporating said air inlet opening and said product outlet opening, a cylindrical cowl being fixed in a sealed manner around said cylindrical sleeve, said cowl being open on the side of the product outlet and including means of fixing the ball in order to keep said ball fixed before its placement in its blocking position in the sleeve and after its removal by the flow of air.
Advantageously, said cowl fixing means for the ball comprise fins arranged on the inside wall of the cowl, so that after its removal from its blocking position, the ball is held fixed in the cowl in a centered fashion so that an optimum discharge of air/powder mixture can flow around it.
Another subject of this invention is a device for the dispensation of a fluid or powder product that comprises an air blast to generate an air flow when the device is actuated and at least one reservoir.
Preferably the air blast comprises a piston closing, preferably in a sealed manner, and sliding within a chamber connected to said reservoir air inlet, said piston being connected to an actuating member, actuated by the user.
As a variant, the air blast comprises a bellows connected to said reservoir air inlet.
Preferably, the reservoir product outlet is connected, preferably in a sealed manner, to an outlet channel, the diameter of which is greater than the diameter of the ball, said channel comprising means of stopping the ball to prevent its expulsion out of the device at the time the product is being expelled.
Preferably, the reservoir air inlet is blocked by a closing membrane that forms a seal to both product and air, the device comprising means of opening the reservoir air inlet designed to open said membrane before the expulsion of the dose of product.
Advantageously, said means of opening the reservoir air inlet comprise a piercing needle fitted to pierce said closing membrane and to connect said reservoir to said air blast.
According to one particular embodiment of the invention, said air blast comprises resetting means of the kind that enables the device to be recharged and/or reused.
Advantageously, the resetting means comprises a spring that returns the piston and the actuating member to their respective stand-by positions.
Advantageously, said reservoir is mounted in a detachable manner in said device in such a way that it can be replaced after each actuation of the device.
It is possible that, before its actuation, the whole of the device is packaged in air-tight packaging.
Another objective of this invention is a method of filling such a powder reservoir, comprising the steps of:
introducing a dose of powder into the sleeve, through the product outlet opening
fitting the cowl around the sleeve, said cowl including the closing ball held fixed by said ball fixing means
inserting the ball into the product outlet opening of the sleeve.